Author, A. A., & Author, B. B. (Year). Title of entry. In A. A. Editor (ed.), Title of reference work (edition). Publisher. URL
Beck, J., & Foley, D. (2010). Music composition. In B. Graves (ed.). The Canadian encyclopedia (2010 ed.). Historica Canada. https://www.thecanadianencyclopedia.ca/en/article/music-composition
Institution or organization name. (Year). Title of entry. In Title of reference work. URL
Merriam Webster. (n.d.). Climate change. In Merriam-Webster.com dictionary. Retrieved June 8, 2020, from https://www.merriam-webster.com/dictionary/climate%20change
Note: When an online reference work is continuously updated and the versions are not archived, use "n.d." as the year of publication and include a retrieval date.
Title of entry. (Year, Month Date). In Wikipedia. Permalink [or URL and retrieval date]
Veterinary medicine. (2020, June 3). In Wikipedia. https://en.wikipedia.org//w/index.php?title=Veterinary_medicine&oldid=960593868
Cite the archived version of the page so that readers can retrieve the version you used. Access the archived version on Wikipedia by selecting "View history" and then the time and date of the version you used. If a wiki does not provide permanent links to archived versions of the page, include the URL for the entry and the retrieval date.
Wikipedia may not be considered an acceptable source for a college or university assignment. Be sure to evaluate the content carefully and check your assignment.